1. Field of the Invention
The present invention relates to the field of building materials and, more specifically, to the field of a concrete modular building system of superior strength.
2. Description of Related Art
Modular building systems exist in the prior art. U.S. Pat. No. 2,462,415 to Nagel teaches building and wall construction using preformed units. Unlike the present invention, Nagel utilizes a metallic peripheral frame (col. 2, lines 14-15) to secure the preformed units together. Similarly, U.S. Pat. No. 3,555,763 to Bloxom teaches a method of forming walls with prefabricated panels with metallic peripheral frames. The metal frames of Nagel and Bloxom add to the cost of construction because of the amount of metal required to create a frame of sufficient strength to support the panel. Assembly of structures using Bloxom's panels is not easy because it requires the use of a crane at the construction site to place them, thereby negating any savings produced by the use of modular components. Bloxom's panels require welding of the entire seam to join them together. Welding the entire seam is time-consuming and subject to human error. In Nagel, adjacent panels are interlocked by the metallic frame. Any errors in the size, shape or location of the interlock, which comprises the entire length of the panel, will cause the panel to fail to fit in its proper location.
U.S. Pat. No. 4,320,606 to GangaRao also teaches buildings formed by assembling a multiplicity of pre-cast reinforced concrete panels. Similar to Bloxom, GangaRao welds metal bars of adjacent panels to connect his panels, a time-consuming and error prone task. U.S. Pat. No. 4,676,035 to GangaRao teaches an additional connection mechanism for the '606 patent. In the '035 patent, GangaRao utilizes smaller L-shaped welding bars to connect panels, resulting in less welding time and reduction in the room for error. Similar to Bloxom, Ganga Rao's panels are not easily conveyed, requiring a crane to properly move and place the panels. Finally, each of Ganga Rao's exterior panels requires a pair of reinforcing rod grids. While these grids add to the stability of the panel, they also add to the expense of the finished product.
U.S. Pat. No. 3,747,287 to Finger teaches a modular building construction method. Similar to Bloxom and Ganga Rao, Finger's panels require a crane to transport them from one spot to another (col. 7, line 15). In addition, Finger's wall panels are trapezoidal in shape, resulting in additional roofing materials and irregular wall shapes. These shapes may also be detrimental to the strength of the building to withstand external forces, such as earthquakes. This lack of strength is evidenced by the requirement of Finger to include reinforcing means on the front and back surfaces of each panel (col. 1, lines 16-18).
A structure utilizing the modules of the present invention requires little heavy machinery to assemble, thereby reducing construction costs. A structure resulting from the modules of the present invention provides superior strength than exhibited by the prior art and requires less materials and work hours to construct.